REGN1908/1909 prevented cat allergen–induced early asthmatic responses in an environmental exposure unit
Authors: Frederic J. de Blay, Alina Gherasim, Nathalie Domis, Pretty Meier, Furat Shawki, Claire Q. Wang, Jamie M. Orengo, Michelle DeVeaux, Divya Ramesh, Jessica J. Jalbert, Mohamed A. Kamal, Hisham Abdallah, Robert Dingman, Lorah Perlee, David.M. Weinreich, Gary Herman, George D. Yancopoulos, Meagan P. O’Brien
Journal: Journal of Allergy and Clinical Immunology (2022)

BackgroundThe dominant allergen in cat dander, Felis domesticus allergen 1 (Fel d 1), is a persistent trigger for allergic rhinitis and asthma symptoms.ObjectiveWe evaluated the efficacy of Fel d 1 monoclonal antibodies (REGN1908/1909) in preventing cat allergen–induced early asthmatic responses (EARs) in cat-allergic patients with mild asthma.MethodsPatients were randomized to single-dose REGN1908/1909 600 mg (n = 29) or placebo (n = 27). The FEV1 was measured for up to 4 hours in a cat allergen environmental exposure unit up to 85 days after dosing. Assessments included between-group differences in change from baseline in FEV1 area under the curve (AUC; 0-2 hours) and incidence of EAR (FEV1 reduction ≥20%). Trial registration: NCT03838731.ResultsSingle-dose REGN1908/1909 significantly prevented reductions in FEV1 on days 8, 29, 57, and 85. Most REGN1908/1909 patients did not have an EAR by 4 hours (the last time point tested). In contrast, placebo-treated patients experienced a ≥20% mean FEV1 reduction on days 8, 29, 57, and 85 after dosing, with most experiencing an EAR within 1 hour. REGN1908/1909-treated patients tolerated 3-fold higher allergen quantities (P < .05 at all time points) versus placebo. REGN1908/1909 substantially reduced skin test reactivity to cat allergen versus placebo at all time points tested (nominal P < .001). REGN1908/1909 was generally well tolerated; no serious adverse events or deaths were reported.ConclusionSingle-dose REGN1908/1909 significantly prevented reductions in FEV1 in cat-allergic patients with mild asthma on cat allergen environmental exposure unit exposure at 8 days and up to 85 days after dose. The dominant allergen in cat dander, Felis domesticus allergen 1 (Fel d 1), is a persistent trigger for allergic rhinitis and asthma symptoms. We evaluated the efficacy of Fel d 1 monoclonal antibodies (REGN1908/1909) in preventing cat allergen–induced early asthmatic responses (EARs) in cat-allergic patients with mild asthma. Patients were randomized to single-dose REGN1908/1909 600 mg (n = 29) or placebo (n = 27). The FEV1 was measured for up to 4 hours in a cat allergen environmental exposure unit up to 85 days after dosing. Assessments included between-group differences in change from baseline in FEV1 area under the curve (AUC; 0-2 hours) and incidence of EAR (FEV1 reduction ≥20%). Trial registration: NCT03838731. Single-dose REGN1908/1909 significantly prevented reductions in FEV1 on days 8, 29, 57, and 85. Most REGN1908/1909 patients did not have an EAR by 4 hours (the last time point tested). In contrast, placebo-treated patients experienced a ≥20% mean FEV1 reduction on days 8, 29, 57, and 85 after dosing, with most experiencing an EAR within 1 hour. REGN1908/1909-treated patients tolerated 3-fold higher allergen quantities (P < .05 at all time points) versus placebo. REGN1908/1909 substantially reduced skin test reactivity to cat allergen versus placebo at all time points tested (nominal P < .001). REGN1908/1909 was generally well tolerated; no serious adverse events or deaths were reported. Single-dose REGN1908/1909 significantly prevented reductions in FEV1 in cat-allergic patients with mild asthma on cat allergen environmental exposure unit exposure at 8 days and up to 85 days after dose.